Out-of-body experiences:
                              Neuroscience or the paranormal?
                                   by Tim Newman from MedicalNewsToday

As you lie in slumber, your spirit body snaps free and drifts upward while your physical shell is left lonely on the bed below, connected only by a fragile, silvery cord. You turn and observe yourself peacefully sleeping. Could this be evidence of the soul? Could it be proof of life after death?

Reports of out-of-body experiences (OBEs) vary. Some consist of little more than a fleeting feeling that body and mind have come loose, while others recount tales of floating far from the person's physical body and traveling to otherworldly plains.

Either way, OBEs have fascinated humanity for centuries, entering folklore, spiritual belief, and mythology.

In the 19th century, for instance, OBEs became a popular topic of the romantic literary movement, and unsurprisingly, they were eagerly discussed by early psychical researchers.

 

I suddenly seemed to divide into two distinct beings. [...] One of these beings remained motionless on the sofa; the other could move some little distance, and could actually look at the motionless body on the sofa."  Journal of Society for Psychical Research, July 1894

 

According to surveys, around ten percent of the population have experienced an OBE at least once - so there must be more to it than a desire to live forever or an over-charged imagination.

 

Although, historically, most research into OBEs has come from the unkempt fringes of science, it has attracted a little more serious attention over recent years. In this article, we will discuss some of these findings.

OBEs have been documented in a variety of situations. These can be split into two categories: spontaneous and induced.

Spontaneous OBEs

A variety of factors could trigger a spontaneous OBE. These include:

 

Sleep: Spontaneous OBEs are most commonly reported as occurring just before falling asleep or just prior to waking. They are more likely to occur when sleep is not particularly deep - due to noise, stress, or illness, for example.

 

Physical effort: OBEs have also been reported following or during extreme exertion.

 

Near-death experiences (NDEs): OBEs sometimes occur alongside "light at the end of the tunnel" visions.

Other spontaneous OBEs have been reported during meditation, non-life-threatening accidents, anesthesia, hypnosis, child birth, when suffocating, after being shot, while dancing or talking, or, as one 36-year-old police officer relates, during her first night at work.

 

When I and three other officers stopped the vehicle and started getting [to] the suspect [...] I was afraid. I promptly went out of my body and up into the air maybe 20 feet above the scene. I remained there, extremely calm, while I watched the entire procedure - including watching myself do exactly what I had been trained to do."
Induced Induced OBEs

  From a scientific standpoint, induced OBEs offer a more tantalizing glimpse into the physical basis of OBEs. They include:

Drugs: Hallucinogenic drugs, and dissociative hallucinogenics in particular - such as DMT, MDA, LSD, and ketamine - can give rise to induced OBEs

Sensory deprivation or overload: Either too little sensory information (floatation tanks or listening to white noise) or too much (torture) can also trigger them.

Strong G-forces: Pilots and astronauts occasionally experience OBEs. For instance, when extreme G-forces are encountered, blood can partially drain from certain parts of the brain. This, it seems, has the power to induce an OBE.

In this instance, OBEs occur as part of a phenomenon called "gravity-induced loss of consciousness." The more surreal parts of this experience are not freely discussed by most pilots, but some give accounts.

"I was there. But I, like, wasn't there. I was floating. I was looking at myself from outside of myself." Col. Dan Fulgham  

It is not only extreme G-forces that can spark OBEs in pilots. Even during standard flights, pilots can endure odd sensory experiences, which are referred to collectively as spatial disorientation (SD). In one particular SD episode, known as the "break-off phenomenon," a pilot may feel as though they are sat on the wing, watching themselves fly the plane.

SD is considered one of the common factors  contributing to aviation accidents.   Fatigue, stress, drugs, low light levels, and sensory overload or deprivation are among the factors potentially involved.

Verifying veridical perception

 

Perhaps the most controversial aspect of OBEs is veridical perception, which is the claim that during an OBE, the viewer is able to literally float out of their body and witness something or someone that they could not have otherwise seen. A well-known example is the case of Pam Reynolds, a brain surgery patient who underwent a highly invasive operation to remove a brain tumor.

Direct brain stimulation

In 1955, Canadian neurosurgeon Wilder Penfield electrically stimulated the brains of people with epilepsy. On one occasion, he stimulated a patient's right temporal lobe and the patient exclaimed, "Oh God! I am leaving my body."

In 2002, a Swiss group also working on patients with epilepsy passed a weak current through a patient's right angular gyrus, which is where the parietal lobe meets the temporal lobe.

This region is also called the temporoparietal junction.The patient relayed a sensation of "falling from a height." As they increased the current, she said, "I see myself lying in bed, from above, but I only see my legs and lower trunk."

Our brains do such a wonderful job of pinning us in reality that we often forget that the pins are an illusion and can, therefore, sometimes be shaken loose. Blanke, one of the scientists involved in the Swiss experiment, believes, "OBEs are related to a failure to integrate multisensory information from one's own body at the temporoparietal junction (TPJ)."In another study conducted by Blanke, he and his team studied six neurological patients with brain lesions that caused them to experience occasional OBEs. They found "the angular gyrus to be involved in all five patients in whom lesion analysis could be performed.

"What does the temporoparietal junction do?

The latest studies position OBEs squarely in the court of the TPJ. So, what do we know about this region of the brain?

The TPJ is an area that collates a range of information. It is a hub of activity, with inputs from the thalamus (which relays sensory information) and the limbic system (which is important in emotion and memory). It also takes data from the visual, auditory, and somatosensory (bodily sensations) systems. The TPJ integrates information from the external environment as well as from within the body. It is thought to play a part in the distinction between self and other, which makes the TPJ a prime contender for the seat of OBEs.

Why OBEs should happen to people who are otherwise healthy is still a mystery. But perhaps the illusion is, physiologically, no more significant than many other tricks of the mind that we take in our stride, such as déjà vu. The difference with OBEs is that they attack our sense of self, something that we hold dear yet take for granted.